I would have greatly preferred that they just remove the card.
Making it a vanilla 3/4 or 4/3 would have even been better.
What's the practical difference between a card you never ever play and a card that doesn't exist?
A card you never play still shows up in Unstable Portal/Piloted Sky Golem. There's a reason people said Darnassus Aspirant was a Piloted Shredder nerf. (Not that Darnassus is a bad card, but it's one of the side effects.)
It also takes up a slot in arena drafting that could be taken by a better card.
Doesn't that make Warsong Commander just like any other crappy card, though? Would you be in favor of removing all crappy cards from the game? None of those seem objectively 'bad', just 'different'. It slightly slightly slightly lowers the power or Unstable Portal (which is already a very powerful card), and it slightly slightly slightly lowers Warrior Arena runs (which is worse, because Warrior is relatively weak in arena), but I don't see what's different between Warsong Commander and every other bad card, and I don't see people clamoring to get rid of all unplayable cards.